Re: New vsyscall emulation breaks JITs

From: Andi Kleen
Date: Fri Aug 05 2011 - 16:27:07 EST


> I have to say I believe that trying to JIT the vdso or vsyscall pages is
> extremely dubious at best. They are fundamentally different from normal
> user space in that the kernel can muck with them any time, without
> notifying userspace about it. The other aspect of this is that this is
> about the legacy vsyscall page, which we're trying to get rid of, partly
> because of security problems.

There's clear evidence now you can't: it's used even by new binaries.

-Andi

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